Background: Overweight and obesity are cardiovascular risk factors becoming more prevalent in later years. There are no studies related to this problem in the atacameña population, which is the third largest group among original inhabitants in Chile. Aim: to evaluate prevalence of overweight and obesity in "atacameños" of northern Chile and to compare these findings in a rural (Alto el Loa) and an urban locations (Calama). Methods: The data obtained from preventive medical examinations performed in primary care centers of Alto el Loan and Calama during 2007 and 2008 were used for the analysis. The subjects included had both paternal and maternal grand parents with "atacameños" surnames. Weigth, height, body mass index, waist circumference, blood pressure, blood glucose level and serum cholesterol were determined. Results: 43 subjects from Alto el Loa and 98 subjects from Calama were included. Weight was normal in 30% of subjects from Alto el Loa; overweight was present in 46.5% and obesity in 23.5%. Corresponding values for subjects from Calama were 25%, 42.7% and 32.3% (NS). The only significantly different variables were serum cholesterol (163 mg/dl in Alto el Loa vs 188 mg/dl in Calama) and waist circumference: (110cm in Alto el Loa vs 99,3 cm in Calama for males, and 113cm in Alto el Loa vs 90.6cm in Calama for women). Conclusion: malnutrition leading to overweight and obesity affected 70% of "atacameños". Lower serum cholesterol levels and increased waist circumference suggest the presence of factors leading to accumulation of abdominal fat in the rural population.